Personal computers are typically small systems that have a processing unit, a display, and several input devices. The display and input devices are coupled to the processing unit, and they often rest on a table or desktop. In most applications, the input devices include a keyboard to transmit alphanumeric commands to the processor and another input device (e.g., a mouse, track-ball or joystick) to control items shown on the display. In operation, keys on the keyboard are selectively pressed to input data or otherwise send commands to the processor.
One problem with operating conventional keyboards is that many people experience fatigue or discomfort in their arms, wrists, and hands. Many people, such as word processors, secretaries, data input personnel, computer programmers, and other computer operators, spend a significant amount of time operating keyboards. Moreover, many people operate keyboards with their arms, hands and wrists in a relatively fixed, unnatural position that induces strain in the muscles and tendons associated with their wrists. As such, a significant number of people experience fatigue or discomfort while operating conventional keyboards. In extreme cases, some people develop carpal tunnel syndrome.
To reduce such fatigue and discomfort, many ergonomic keyboards have been developed with various shapes and keypads. For example, instead of a rectilinear keyboard, many ergonomic keyboards are non-linear and have split keypads so that the left-hand keys extend along one axis and the right-hand keys extend along another axis. Additionally, some ergonomic keyboards may also have a convex upper surface with respect to the desktop. Although most people find ergonomic keyboards to be more comfortable than rectilinear keyboards, many people prefer to use conventional rectilinear keyboards with conventional linear keypads because they make fewer mistakes with rectilinear keyboards. Additionally, many people still experience significant discomfort with ergonomic keyboards because muscle strain may still build over long periods of time causing fatigue or even carpal tunnel syndrome. Therefore, conventional rectilinear keyboards and even ergonomic keyboards may not be comfortable to use for significant periods of time.